Method and device for diagnosing in a motor vehicle a driver&#39;s fitness drive

ABSTRACT

The invention relates to a method for diagnosing the driving capability of a driver of a motor vehicle ( 5 ), in which changes in driver condition are ascertained from physiological measured values derived from the driver while driving in the vehicle and evaluated, and if the changes are serious, a warning is issued or remedial actions are initiated, wherein the physiological measured values ascertained while driving in the vehicle are combined by means of a corresponding expert system ( 10 ) with health-relevant data for the driver ascertained in stationary fashion, and with data indicating driver stress that are estimated in particular from the instantaneous traffic situation and instantaneous operating state of the vehicle ( 5 ), and changes in the driver&#39;s condition are weighted with the estimated driver stress and interpreted; and an apparatus ( 1 ) for carrying out the method, which is characterized in that the expert system ( 10 ) is implemented in an onboard computer of the vehicle ( 3 ) which is connected via a bus ( 3 ) internal to the vehicle to a mobile driver condition sensor suite ( 4 ) that supplies the physiological measured values; to a memory/transfer medium ( 15, 18 ) that delivers the biographical data and/or the health-relevant data ascertained in stationary fashion; and to an ACC system and driving direction system ( 11 ) internal to the vehicle.

BACKGROUND INFORMATION

[0001] The invention relates to a method for diagnosing the drivingcapability of a driver in a motor vehicle, in which changes in drivercondition are ascertained from physiological measured values derivedfrom the driver while driving in the vehicle, and if the changes areserious, a warning is issued or remedial actions are initiated; as wellas an apparatus for performing this method.

[0002] Systems which appraise the driver's condition on the basis ofphysiological parameters measured in the vehicle are known. Theseinclude, for example, interactive systems that request from the driver,while driving, certain input actions on the basis of which the drivingcapability of the driver is determined. Systems also exist which sensethe eyelid blink frequency by way of a video camera with downstreamimage analysis. From the acquired blink frequency, conclusions can inturn be drawn regarding the driving capability of a driver in the motorvehicle.

[0003] Also available in the home context are systems, for exampleexercise machines equipped with ergometric functions, which allowconclusions as to the health of the user by way of physiologicalmeasured values such as blood pressure, pulse rate, skin impedance, etc.

[0004] The informativeness of systems that are currently known or underdevelopment in terms of assessing the driving capability of the driverin a motor vehicle is considerably limited, however, by the fact thatthe only methods possible are those that do not use fixed electrodes orcatheters on the driver's body, but instead must make do with contactson bare skin areas or with entirely non-contact measurements, such asthe aforesaid acquisition of the eyelid blink frequency by means of avideo camera.

OBJECT AND ADVANTAGES OF THE INVENTION

[0005] It is the object of the invention to increase the reliability andinformativeness of a method of the species for diagnosing the drivingcapability of a driver of a motor vehicle in order, as applicable, tooutput to the driver a warning based on the diagnosis of drivingcapability and to initiate remedial actions if necessary.

[0006] According to one significant aspect, in the context of the methodaccording to the present invention the physiological measured valuesmeasured instantaneously while driving are combined with stationaryhealth-relevant data for the driver ascertained in the home context, andare weighted and interpreted by an expert system with data, present inthe vehicle or derived, indicating driver stress, in particularconcerning the instantaneous traffic situation and the instantaneousvehicle operating state or changes in the driver's condition.

[0007] This makes it possible to use the data obtained in the vehiclefrom the vehicle operating state and from the instantaneous trafficsituation to derive an estimated value regarding the instantaneousdriver stress, with which the instantaneous physiological data about thedriver measured while driving in the vehicle, and the stationaryhealth-relevant data obtained in the home context and combinedtherewith, can then be weighted and interpreted in a more informativefashion to yield a comprehensive appraisal of the driver's drivingcapability.

[0008] Circulatory data such as the driver's pulse rate and bloodpressure are particularly suitable for the acquisition of physiologicalvalues for the driver in the vehicle. Such circulatory data can easilybe obtained with already known transducers, for example, in the form ofa wristwatch, and transmitted wirelessly to a receiver in the vehicle.

[0009] Also suitable is measurement in the vehicle of the driver's skinimpedance. This physiological value can also be obtained using alreadyknown transducers that are attached to the driver's skin, andtransmitted wirelessly to a receiver in the vehicle.

[0010] Mention has also already been made of the possible measurement,using a video camera with downstream image processing, of the eyelidblink parameter, i.e. the driver's blink frequency and speed, which canprovide clear information about driver fatigue.

[0011] An estimate of the instantaneous stress on the driver as a resultof the situation in terms of driving, traffic, and the environment canbe made from data that are derivable or present in any case in thevehicle. For example, data from a destination guidance system can beused. These indicate the static traffic situation in which the driverfinds him- or herself, e.g. urban, rural, at a complex intersection, ona narrow mountain road. Information regarding the dynamic trafficsituation is obtained from road condition data, weather data, and timeof day; by way of the sensed speed of the particular vehicle, forexample acceleration values and frequency; and from the speed of othervehicles, for example based on ACC signals. An estimate of theinstantaneous traffic density, based on ACC data and using future videosensor apparatus, appears possible in principle.

[0012] In the method according to the present invention, the estimatethat is made of the instantaneous driver stress is combined, by the useof an expert system, with the instantaneous physiological situation ofthe driver as supplied by the aforementioned physiological data acquiredwith the use of a driver condition sensor suite. As a result of thisassociation, it is possible to determine how the stress due to drivingis reflected in the physiological data. It is assumed in this contextthat other influences, for example interaction with passengers or inconversations by mobile telephone in traffic, have much less of aninfluence on the driver's stress level. Stress resulting from drivingserves, in a way, as an “ergometer” with which a patient, i.e. in thiscase the driver, is brought into a known stress situation. Thedifference here is also that driving represents more a mental andpsychological stress than a physical one. From the physiologicalreaction of the driver's body to this stress, conclusions can then bedrawn as the state of the driver's health. For example, extreme systolicblood-pressure values and rapid pulse rates may occur, and adetermination can be made as to whether they are correlated withdifficult traffic situations or are occurring without such stresses. Inthe latter case, the driver can be warned and can be advised to seekmedical help. Information as to excessive fatigue or drugs (such asblood alcohol level) can be obtained in known fashion from measuredvalues of the driver condition sensor suite operated in the vehicle. Asa result of this weighting with the driver stress estimated from thetraffic situation and from the vehicle operating status, considerablybetter conclusions can be drawn as to the relevance of this information.

[0013] In the method according to the present invention, as mentioned,the instantaneous physiological data obtained using the mobile drivercondition sensor suite in the vehicle are also combined withhealth-relevant data for the driver ascertained on a stationary basis.Stationary health data of this kind can be ascertained, for example,using home-based systems that are capable of obtaining from the user's(in this case the driver's) biological material, such as urine, feces,sweat, etc., information about the person's state of health.Health-relevant data can also be collected and stored in home healthdevices, for example bicycle ergometers, exercise machines, blood-sugarmeasurement instruments, scales, etc. These stationary data are usuallyobtained in static situations or during muscle work, and notpredominantly under mental/psychological stress such as occurs in amotor vehicle. The stationary data can be stored in a suitablestorage/transfer medium, and the latter can be read by an input means inthe vehicle or the stored information can be sent to a receiver in thevehicle. This memory/transfer medium can be, for example, a chip card, awristwatch with wireless transmission technology, a mobile radio system,or the like.

[0014] The expert system in the motor vehicle weights the instantaneousphysiological data (obtained while driving using the mobile drivercondition sensor suite) with the driver's health-relevant data obtainedin stationary fashion, and thereby obtains a more comprehensive pictureof the driver's state of health, so that in the event of seriousdeviations from normal values, remedial actions can be initiated asapplicable.

[0015] In the event no stationary measured values concerning thedriver's state of health in the home context can be obtained, standardvalues are assumed by the diagnostic method proposed according to thepresent invention, and those standard values are refined using inputtedbiographical data such as the driver's gender, age, and weight.

[0016] In an embodiment, the expert system can be set up as a learningsystem; initially, before a valid diagnosis as to driving capability isissued, a learning phase with at least one test drive by the driver isperformed in the vehicle, comprising a variety of stress levels andtraffic situations.

[0017] An apparatus set up to carry out the method contains the expertsystem implemented in an onboard computer of the vehicle, and theonboard computer is connected via a vehicle bus system to the drivercondition sensor suite which supplies the physiological measured values;to a memory/transfer means that delivers the biographical data and/orhealth-relevant data ascertained in stationary fashion; to means thatestimate the driver stress based on the instantaneous traffic situationand the instantaneous vehicle operating state and transmit it to theonboard computer; and also to means that impart to the driver as awarning signal, or that emit to the environment, a signal indicating anoverload or a driver stress that is not appropriate for the situation.An ACC system and a vehicle navigation system can be used to ascertainthe instantaneous traffic situation and to appraise the driver stress.In order to identify the driver, the onboard computer and the expertsystem residing therein can be connected to a vehicle accessauthorization control unit.

[0018] The description below describes, with reference to a functionalblock diagram depicted in the FIGURE, steps of a driver diagnosis methodaccording to the present invention, as well as functions of an exemplaryembodiment of an apparatus set up to carry out the method.

EXEMPLARY EMBODIMENT

[0019] System 1, depicted in the FIGURE in the form of functionalblocks, includes the following functional units:

[0020] an expert system 10 implemented in an onboard computer;

[0021] an ACC and navigation system 11 having associated sensors 2 a, 2b and a radio antenna 2 c;

[0022] means 12 for acquiring the stationary (at-home) physiologicaldata of a driver;

[0023] means 15, 18 for storing/transferring to the onboard computer thehealth-relevant data obtained in stationary fashion;

[0024] a vehicle bus system 3 for connecting various units in thevehicle; and

[0025] a driver condition sensor suite 4 located in vehicle 5.

[0026] An optionally provided driver access authorization control unitis not depicted.

[0027] Sensors 2 a, 2 b associated with ACC and navigation system 11,and radio antenna 2 c, serve to acquire environmental/traffic situation20, for example via radar waves, video image acquisition, and/orultrasonic waves, and to receive driving direction information via GSMmobile radio. In ACC and navigation system 11, ACC information 20acquired by the corresponding sensors 2 a, 2 b and antenna 2 c—forexample the number, speed, and heading of other vehicles, and drivingdirection information; also the vehicle's own heading and speed, roadcategory, urban/rural, weather data, road condition, topographic data,etc.—is ascertained, and the driver stress is estimated therefrom andtransmitted in the form of a signal 14 to expert system 10 in theonboard computer. Expert system 10 also receives, from mobile drivercondition sensor suite 4, signals 17 that indicate the physiologicaldata for the driver in the vehicle acquired by driver condition sensorsuite 4. The physiological data ascertained in stationary home-basedsystem 12, as well as biographical data, are inputted viamemory/transfer medium 15 (i.e. a chip card), using an input/read medium18, into expert system 10. In the latter, the stationary health datathus inputted are combined with the instantaneous physiological data 17for the driver acquired by mobile driver condition sensor suite 4 whiledriving, weighted with estimated value 14 for driver stress, andinterpreted.

[0028] Expert system 10 weights the physiological and biographical datawith the estimated driver stress 14 and, if the changes in drivercondition are serious, generates a warning for the driver and/or asignal 13, e.g. emittable externally via GSM radio, which indicates theoverload or situationally inappropriate stress on the driver so thatremedial actions can be initiated. In one embodiment, the onboardcomputer or expert system can be connected to a driver accessauthorization control unit which performs the identification of thedriver and delivers it to the expert system.

[0029] The core of the method according to the present invention, and ofthe apparatus according to the present invention set up to carry out themethod, is thus the combination, performed by the expert system, ofphysiological data 17 (obtained while driving by way of driver conditionsensor suite 4) with the stationary health-relevant data obtained in thehome context and delivered via memory/transfer medium 15, and theweighting of these combined data using an estimated value 14 thatindicates driver stress, which is estimated as an independent variablebased on the traffic situation and driving direction informationobtained from the onboard ACC and navigation system 12 and is deliveredto expert system 10. From the weighted change in driver condition,expert system 10 decides if that change is so serious that drivingcapability is questionable, if a warning signal needs to be issued tothe driver, or if applicable remedial actions need to be initiated.

[0030] In the exemplary embodiment described above, expert system 10resides in an onboard computer of a vehicle 5. The method according tothe present invention is not, however, limited to this currentlypreferred exemplary embodiment, but rather is also usable if expertsystem 10 resides outside vehicle 3 at a central location, to which thephysiological data ascertained by way of the mobile driver conditionsensor suite, the stationary physiological and biographical data, andthe information about the traffic situation and the driving directioninformation ascertained from the ACC system and navigation system 12 arethen conveyed.

[0031] The invention was described above for an application aimed atascertaining the driving capability of the driver of a motor vehicle. Itis nevertheless immediately apparent to those skilled in this art thatthe invention is also applicable to operating capability diagnosis inthe context of drivers (or pilots) of other vehicles and means oftransportation, for example ships, aircraft, and rail vehicles. The term“motor vehicle” or “vehicle” used in the above description and in theClaims is thus to be construed broadly.

What is claimed is:
 1. A method for diagnosing the driving capability ofa driver of a motor vehicle, in which changes in driver condition areascertained from physiological measured values derived from the driverwhile driving in the vehicle and evaluated, and if the changes areserious, a warning is issued or remedial actions are initiated, whereinthe physiological measured values acquired while driving in the vehicleare combined by an expert system with health-relevant data, ascertainedin stationary fashion or estimated, for the driver; and changes indriver condition are weighted and interpreted by the expert system witha variable indicating driver stress that is estimated from data presentor derived in the vehicle, in particular concerning the instantaneoustraffic situation and instantaneous vehicle operating state, in order todetect whether or not the driver is capable of driving.
 2. The method asdefined in claim 1, wherein circulatory measured values, in particularthe pulse rate and blood pressure of the driver in the vehicle, aresensed as physiological measured values.
 3. The method as defined inclaim 1 or 2, wherein the impedance of the driver's skin is sensed inthe vehicle as a physiological measured value.
 4. The method as definedin one of the foregoing claims, wherein an electrocardiogram of thedriver is measured in the vehicle as a physiological measured value. 5.The method as defined in one of the foregoing claims, wherein the eyelidblink frequency of the driver is sensed in the vehicle as aphysiological measured value.
 6. The method as defined in one of theforegoing claims, wherein physiological data measured in stationaryfashion in the driver's home context, for example ergometric datameasured on ergometric devices, and biographical data such as age,weight and gender, are used as health-relevant data.
 7. The method asdefined in one of the foregoing claims, wherein blood analysis values,e.g. the blood sugar level, of the driver obtained in the home contextare used as health-relevant stationary data.
 8. The method as defined inone of the foregoing claims, wherein if no stationary health-relevantphysiological measured values concerning the driver are measurable orare present, standard values are assumed and are refined using inputtedbiographical data such as gender, age, and weight.
 9. The method asdefined in one of the foregoing claims, wherein the instantaneoustraffic situation is estimated from the number, speed, and heading ofother vehicles and from relevant driving direction information for thevehicle, and combined with instantaneous operating state data for therelevant motor vehicle, in particular its own heading and speed, and thedriver stress is calculated therefrom.
 10. The method as defined in oneof the foregoing claims, wherein a learning system is used as the expertsystem; and initially, before a valid diagnosis of driving capability isissued, a learning phase with at least one test drive by the driver isperformed in that vehicle, comprising a variety of stress levels andtraffic situations.
 11. An apparatus for carrying out the method asdefined in one of claims 1 through 10, wherein the expert system (10) isimplemented in an onboard computer of the motor vehicle (5) which isconnected via a vehicle bus (3) to a vehicle-based driver conditionsensor suite (4) supplying the physiological measured values; to amemory/transfer means (15, 18) that delivers the biographical dataand/or the health-relevant data estimated or ascertained in stationaryfashion; to means (11) for ascertaining and transferring to the onboardcomputer the instantaneous traffic situation (20) and the instantaneousoperating state data of the motor vehicle (5); and to transmission means(13) for transferring to the environment a signal indicating an overloador a driver stress that is not appropriate for the situation.
 12. Theapparatus as defined in claim 11, wherein the mobile vehicle statussensor suite (4) in the vehicle (5) includes at least a pulse andblood-pressure meter.
 13. The apparatus as defined in claim 11 or 12,wherein the mobile vehicle status sensor suite (4) in the vehicle (5)includes at least a skin impedance sensor.
 14. The apparatus as definedin one of claims 11 through 13, wherein the mobile vehicle status sensorsuite (4) in the vehicle (5) includes at least an electrocardiograph.15. The apparatus as defined in one of claims 11 through 14, wherein themobile vehicle status sensor suite (4) in the vehicle (5) includes avideo camera with downstream image evaluation system, in particular forsensing and evaluating the driver's eyelid blink frequency.
 16. Theapparatus as defined in one of claims 11 through 15, wherein thememory/transfer means (15, 18) include a memory medium (15) such as achip card, and an input/read apparatus (18) which reads the latter andis connected to the onboard computer.
 17. The apparatus as defined inone of claims 11 through 16, wherein an ACC system and vehiclenavigation system (11) connected to corresponding sensors (2 a, 2 c) isprovided as the means for ascertaining and transferring theinstantaneous traffic situation (20).
 18. The apparatus as defined inone of claims 11 through 17, wherein a radio transmission system, inparticular a GSM mobile data radio system, is provided as thetransmission means (13).
 19. The apparatus as defined in one of claims11 through 18, wherein the onboard computer containing the expert system(10) is connected to an access control unit of the vehicle whichperforms an identification of the driver.